The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory captions and links exemplifying features within the Earth system. The community is invited to contribute digital imagery, short captions and relevant links.

Golden Gate Bridge

The Golden Gate Bridge opened for vehicular traffic on May 28, 1937. Since then the Bridge has been a symbol of San Francisco though it no longer has the distinction of containing the world’s longest suspension span. It even has a slight influence on San Francisco’s famous and diverse fogs. In the summer, advection fog is caused as cold water brought south down the coast by the California Current rises to the surface along the California coast replacing the warmer surface water. The meeting of this colder water and the warm surface air can cause frequent fog. In a way, the bridge affects fog in that the towers and suspension cables tend to direct the flow of the fog as it rises and falls. The color of the bridge, international orange, was chosen in part because of its high visibility in foggy conditions. On May 28, 2012, the 75 birthday of the Golden Gate Bridge was celebrated with a wonderful fireworks display. The guest of honor looks pretty much the same as it did three-quarters of a century ago. The bridge is named for the strait it spans. These straits were probably named Golden Gate in the mid-nineteenth century by John C. Fremont who felt the channel was reminiscent of the Golden Horn harbor of Istanbul.